Which of the following is not true of an atom that has an atomic number of 19 and a mass number of 41?
A) The atom contains 22 neutrons.
B) The atom is potassium.
C) The atom contains 19 neutrons.
D) The atom contains 19 electrons.
E) The atom contains 19 protons.

Question

Quizplus · Accepted Answer

The atomic number represents the number of protons in an atom, which is 19 in this case. The mass number represents the total number of protons and neutrons in the atom, which is 41 in this case. Therefore, to find the number of neutrons, we subtract the atomic number from the mass number: 41 - 19 = 22. So, the correct statement is that the atom contains 22 neutrons, not 19.

Which of the Following Is Not True of an Atom